Popular smoking articles, such as cigarettes, have a substantially cylindrical rod shaped structure and include a charge of smokable material, such as shreds or strands of tobacco material (i.e., in cut filler form), surrounded by a paper wrapper, thereby forming a tobacco rod. It has become desirable to manufacture a cigarette having a cylindrical filter element aligned in an end-to-end relationship with the tobacco rod. Typically, a filter element includes cellulose acetate tow circumscribed by plug wrap, and is attached to the tobacco rod using a circumscribing tipping material. Many cigarettes include processed tobacco materials and/or tobacco extracts in order to provide certain flavorful characteristics to those cigarettes.
Flavor and aroma are important characteristics of smoking articles. To improve the flavor and aroma in smoking articles, flavorful and aromatic substances, including various natural extracts, have been included in smoking articles.
For example, U.S. Pat. No. 3,424,171 describes a process for the production of a non-tobacco smokable product having a tobacco taste. Tobacco is subjected to a moderate (i.e. below scorching) heat treatment i.e., at from about 175.degree. to 200.degree. C. (350.degree. C. to 400.degree. F.), to drive off aromatic components. These components are trapped on adsorbent charcoal, and removed from the charcoal by solvent extraction. The smokable product disclosed is vegetable matter, treated with the mixture of tobacco aromatic components and the solvent.
Similarly, U.S. Pat. No. 4,150,677 describes a process for the treatment of tobacco which comprises the steps of: (1) contacting tobacco which contains relatively high quantities of desirable flavorants with a stream of non-reactive gas, under conditions whereby the tobacco is heated in a temperature range from about 140.degree. to 180.degree. C.; (2) condensing the volatile constituents of the resulting gaseous stream; and (3) collecting said condensate. The condensate may be used subsequently to flavor a smoking material in order to enhance the organoleptic qualities of its smoke.
U.S. Pat. Nos. 5,038,802 to White et al. and 5,016,654 to Bernasek et al. disclose extraction processes which heat tobacco and then pass an inert atmosphere through the heating chamber to collect volatiles from the tobacco. The volatiles are then fractionated in downstream operations, which include liquid sorbents, cold temperature traps, and filters.
Flavorful and aromatic substances can also be produced from reactions of chemical materials in vitro or by adding chemicals to tobacco and reacting such added chemicals with endogenous compounds within tobacco materials.
For example, U.S. Pat. No. 3,478,015 to Onishi et al. discloses making aromatic materials by heating an amino acid and a sugar in the presence of a polyhydric alcohol. Similarly, U.S. Pat. No. 4,306,577 describes reacting reducing sugars and selected amino acids in the presence of ammonium hydroxide and optionally in the presence of an aldehyde. The flavorful materials produced can be incorporated into tobacco materials.
While these processes have produced flavor substances acceptable for use in many smoking articles, they have either been based on non-tobacco materials, or necessarily required the forming of a tobacco extract prior to the obtaining of the desired compound. Moreover, many of these processes required multiple steps of processing.